Method for Transmitting Torque and Variably Flexing a Corrugated Insertion Device

ABSTRACT

A method for transmitting torque and variably flexing an insertion device for receiving an instrument includes the steps of providing a hollow body, transmitting torque along the hollow body with a corrugated tube, applying suction to create a vacuum in the hollow body for placing the hollow body in a relatively stiff condition, relieving the vacuum for placing the hollow body in a relatively flexible condition, maintaining the hollow body in the relatively flexible and relatively stiff conditions with tendons disposed within the hollow body, and individually adjusting at least some of the tendons in length for steering a distal end of the hollow body.

CROSS-REFERENCE TO RELATED APPLICATION

This application is:

a divisional of U.S. patent application Ser. No. 12/432,351, filed onApr. 29, 2009;

a divisional of U.S. patent application Ser. No. 11/502,322, filed onAug. 10, 2006;

and

a divisional of Attorney Docket No. Endoguide 3 DIV2, filed concurrentlyherewith, the entire disclosures of which are hereby incorporated hereinby reference in their entireties.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a torque-transmitting, variably-flexible,corrugated insertion device. The invention also relates to a method fortransmitting torque and variably flexing a corrugated insertion device.

2. Description of the Related Art

Prior art insertion devices of this general type have been quitecomplicated, cumbersome and difficult to use. Such devices have arelatively large diameter, a limited maximum length, a limitedtransmission of torque and present obstacles to insertion ofinstruments.

SUMMARY OF THE INVENTION

p It is accordingly an object of the invention to provide atorque-transmitting, variably-flexible, corrugated insertion device anda method for transmitting torque and variably flexing a corrugatedinsertion device, which overcome the hereinafore-mentioned disadvantagesof the heretofore-known devices and methods of this general type andwhich are simpler to construct, have a smaller diameter, a greatertorque transmission, may be made longer and allow smooth insertion of aninstrument.

With the foregoing and other objects in view there is provided, inaccordance with the invention, a method for transmitting torque andvariably flexing an insertion device for receiving an instrumentincluding the steps of providing a hollow body, transmitting torquealong the hollow body with a corrugated tube, applying suction to createa vacuum in the hollow body for placing the hollow body in a relativelystiff condition; relieving the vacuum for placing the hollow body in arelatively flexible condition, maintaining the hollow body in therelatively flexible and relatively stiff conditions with tendonsdisposed within the hollow body, and individually adjusting at leastsome of the tendons in length for steering a distal end of the hollowbody.

The corrugated tube supports the insertion device and maintains atubular shape, without the need for a support spring. Therefore, theinsertion device has a narrower diameter, may have a longer length, suchas 50 inches or longer, transmits greater torque than a spring and doesnot impair the insertion of an instrument in contrast to a spring.

In accordance with another feature of the invention, there is providedan inner liner within the corrugated tube for preventing vacuum leakageand aiding in insertion of the instrument. The liner may be adhesivelyconnected to the corrugated tube.

In accordance with a further feature of the invention, there areprovided tendons within the hollow body for maintaining the hollow bodyin the relatively flexible and relatively stiff conditions. In asteerable embodiment of the device, some of the tendons are individuallyadjustable in length for steering the distal end of the hollow body. Thetendons and the corrugated tube are at least partly disposed between anouter jacket and an inner sleeve where the transitioning device, such asa vacuum connection, applies suction for frictionally locking thetendons and the corrugated tube in place.

In accordance with an added feature of the invention, inner and outerhandles of the hollow body define a vacuum plenum volume therebetweencommunicating between the outer jacket and the inner sleeve and with avacuum port. A sliding valve encircles the outer handle and has a vacuuminlet/outlet for communicating with the vacuum connection. The slidingvalve slides between a position in which the vacuum inlet/outletcommunicates with the vacuum port and a position in which the vacuuminlet/outlet is sealed against the vacuum port. The sliding valve has arecessed O-ring for sealing the sliding valve to the outer handle. Thisprovides a convenient way for the operator of the device to adjust thestiffness while manipulating the device.

In accordance with an additional feature of the invention, the tendonsextend substantially entirely over a flexible section of the hollow bodybeyond the handle. The tendons float in the handle when the hollow bodyis in the relatively flexible condition. The tendons are not in tensionor compression when the hollow body is in both the relatively flexibleand relatively stiff conditions. The tendons are rigidly attached at thedistal end and allowed to float at the handle. In this regard, there isprovided a termination bushing at the distal end to which at least someof the tendons are attached. Each two of the tendons form legs of aU-shaped configuration passing through holes in the termination bushingand being interconnected by a crosspiece extending between two of theholes distally of the termination bushing, like a large staple. Thisavoids the need to weld the tendons in place at the distal end andremoves the danger of welds breaking at the distal end. The tendonsinclude steering tendons attached to the termination bushing andnon-steering tendons attached to one of the vertebrae.

In accordance with yet another feature of the invention, the tendonsvary in number along the hollow body for providing zones of varyingstiffness. The number of tendons may be greater toward the distal endthan toward the proximal end for increasing stiffness at the distal end.

In accordance with yet another feature of the invention, there areprovided knobs each sliding in a respective slot formed in the handle.The individually adjustable tendons are each steering tendons connectedto a respective one of the knobs for steering the distal end. Thisallows the operator of the device to easily steer the distal end in anydirection.

In accordance with yet another feature of the invention, the corrugatedtube has at least one cuffed end. The cuffed end or ends prevent vacuumleakage and thus preserve stiffness, when required.

In accordance with yet a further feature of the invention, vertebrae aredisposed along the corrugated tube for guiding the tendons. Thevertebrae may be disposed between corrugation peaks of the corrugatedtube and may be elastic and have a parting line to be opened into a gapfor snapping the vertebrae onto the corrugated tube. At least some ofthe vertebrae have channels formed therein permitting movement of atleast some of the tendons therethrough.

In accordance with another mode of the invention, there is provided thestep of preventing vacuum leakage and aiding in insertion of theinstrument with a liner disposed within the corrugated tube.

In accordance with a further mode of the invention, there is providedthe step of adhesively connecting the liner to the corrugated tube.

In accordance with an added mode of the invention, there is provided thestep of providing the hollow body with an outer jacket and an innersleeve, providing the tendons at least partly between the outer jacketand the inner sleeve, providing the corrugated tube between the outerjacket and the inner sleeve, and carrying out the step of applyingsuction between the outer jacket and the inner sleeve with atransitioning device for frictionally locking the tendons and thecorrugated tube in place.

In accordance with yet another mode of the invention, there is providedthe step of individually adjusting at least some of the tendons assteering tendons with knobs each connected to a respective one of thesteering tendons and each sliding in a respective slot formed in ahandle at a proximal end of the hollow body.

In accordance with yet an added mode of the invention, there is providedthe step of providing a vacuum connection as the transitioning device,and actuating the vacuum connection with a valve at the handle.

In accordance with yet an additional mode of the invention, there isprovided the step of guiding the tendons with vertebrae disposed alongthe corrugated tube.

In accordance with again another mode of the invention, there isprovided the step of placing the vertebrae between corrugation peaks ofthe corrugated tube for guiding the tendons.

In accordance with again a further mode of the invention, there isprovided the step of snapping the vertebrae onto the corrugated tube byelastically opening the vertebrae at a parting line into a gap.

In accordance with again an added mode of the invention, there isprovided the step of permitting movement of at least some of the tendonsthrough channels formed in at least some of the vertebrae.

In accordance with again an additional mode of the invention, there isprovided the step of attaching at least some of the tendons to atermination bushing at a distal end of the hollow body.

In accordance with still another mode of the invention, there isprovided the step of forming each two of the tendons into legs of aU-shaped configuration passing through holes in the termination bushingand being interconnected by a crosspiece extending between two of theholes distally of the termination bushing.

In accordance with still a further mode of the invention, there isprovided the step of attaching some of the tendons to a terminationbushing at a distal end of the hollow body as steering tendons,attaching others of the tendons to one of the vertebrae as non-steeringtendons, and steering the distal end with the steering tendons.

In accordance with still an added mode of the invention, there isprovided the step of varying the number of the tendons along the hollowbody for providing zones of varying stiffness.

In accordance with still an additional mode of the invention, there isprovided the step of providing a greater number of the tendons toward adistal end than toward a proximal end of the hollow body, for increasingstiffness at the distal end.

In accordance with a concomitant mode of the invention, there isprovided the step of cuffing at least one end of the corrugated tube toprevent vacuum leakage.

Other features which are considered as characteristic for the inventionare set forth in the appended claims.

Although the invention is illustrated and described herein as embodiedin a torque-transmitting, variably-flexible, corrugated insertion deviceand a method for transmitting torque and variably flexing a corrugatedinsertion device, it is nevertheless not intended to be limited to thedetails shown, since various modifications and structural changes may bemade therein without departing from the spirit of the invention andwithin the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however,together with additional objects and advantages thereof will be bestunderstood from the following description of specific embodiments whenread in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a diagrammatic, side-elevational view of atorque-transmitting, variably-flexible, corrugated insertion deviceaccording to the invention, in which an outer jacket has been partlyremoved to show corrugations, tendons and vertebrae and in which thedevice has been steered to the right;

FIG. 2 is a side-elevational view of the insertion device in whichcorrugations are illustrated at the distal tip as in FIG. 1 and in whichan outer covering of a handle has been removed;

FIG. 3 is a perspective view showing stiffener zones of the insertiondevice and illustrating corrugations at the distal tip;

FIGS. 4 and 5 are fragmentary, side-elevational views of a steeringassembly of the insertion device with corrugations illustrated indifferent locations;

FIG. 6 is an enlarged, fragmentary, longitudinal-sectional view of adistal tip region of the insertion device;

FIG. 7 is a view of the insertion device similar to FIG. 6, in whichtendons have been shown;

FIG. 8 is an elevational view of a corrugated tube of the insertiondevice in which straight and stepped cuffs have been shown;

FIG. 9 is a fragmentary, longitudinal-sectional view of the insertiondevice in which an inner liner, an inner handle and a corrugation cuffhave been shown;

FIG. 10 is a fragmentary, perspective view of the distal tip region ofthe insertion device;

FIG. 11 is a fragmentary, perspective view of the distal tip region ofthe insertion device in which the outer jacket has been removed to showthe tendons, the vertebrae and the corrugations;

FIG. 12 is a view of the insertion device similar to FIG. 11, in whichthe tip has been removed;

FIG. 12A is an enlarged, perspective view of a U-shaped tendon;

FIG. 13 is a view of the insertion device similar to FIGS. 11 and 12, inwhich the tip and a termination bushing have been removed;

FIG. 14 is a cross-sectional view of the insertion device, which istaken along a line IVX-IVX of FIG. 11, in the direction of the arrows;

FIG. 15 is a further enlarged, perspective view of a snap vertebra ofthe insertion device; and

FIG. 16 is a perspective view of a continuous vertebra of the insertiondevice.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the figures of the drawings in detail and first,particularly, to FIG. 1 thereof, there is seen a torque-transmitting,variably-flexible, corrugated insertion device 1 according to theinvention. The insertion device 1 has a hollow body with a proximal end2 for manipulation by an operator and for receiving an instrument suchas an endoscope or a colonoscopy. The insertion device 1 also has adistal end 3 for insertion into a patient and for protrusion of theinstrument. A handle 4 of the hollow body for control by the operator isdisposed at the proximal end 2. An outer jacket 5 of the hollow bodyextends to a tip 7, which may be formed of rubber, at the distal end 3,but only a portion of the outer jacket has been shown in order toillustrate other details of the device disposed within the outer jacket5. A flexible strain relief retainer 6 is disposed between the handle 4and the outer jacket 5. The outer jacket 5 and the flexible strainrelief retainer 6 provide a flexible section with a given lengthextending beyond the handle 4. The handle 4 has a sliding valve 28 and aseptum valve assembly 29, which will be explained in greater detailbelow with regard to FIG. 2. The handle 4 also has a vacuum connectionor nipple 35 for controlling stiffness of the device, as will beexplained below as well. A corrugated tube 30, which is only illustratedin the region of the distal tip 7, actually extends to the flexiblestrain relief retainer 6.

The insertion device 1 may be steerable or non-steerable. If the deviceis steerable, a steering assembly 10 is provided which includes sixvertebrae 13-18 shown as being disposed along the hollow body. However,more or fewer vertebrae can be provided in dependence on the length,diameter and use of the hollow body. Eight tendons 11, 11′ are equallyspaced apart about the circumference of the hollow body between thevertebra 17 and the handle 4, although only five can be seen in FIG. 1.Four of the tendons which extend from a tendon termination bushing 31 atthe tip 7 to the handle 4 are so-called steering tendons 11′. Othertendons which only extend between the vertebra 17 and the handle 4 areso-called non-steering tendons 11.

Each of the four steering tendons 11′ is attached at its proximal end toa respective knob 36 which slides within a respective slot 38 in thehandle 4. A stop 39 is also disposed on each tendon 11′. When a knob 36is slid proximally, it pushes a stop 39 and pulls a tendon 11′ to steerthe hollow body. In the condition shown in FIG. 1, the knob 36 at thebottom has been slid proximally so that the tip 7 of the hollow body hasbeen steered downward. If different knobs 36 are moved, the hollow bodywill be steered in different directions. When the knobs 36 are forceddistally, the knobs can freely slide independently of the tendons 11′ toprevent buckling of the tendons 11′. It will be readily understood thatif two of the knobs are slid proximally, the tip 7 will move in adirection between the two directions that each one of the knobs wouldhave moved the tip if moved individually.

In FIG. 2, an outer covering of the handle 4 has been removed to showdetails of the sliding valve 28 and the septum valve assembly 29. Thehandle 4 has an inner handle 19 disposed within an outer handle 18,defining an annular vacuum plenum volume 24 therebetween which extendsin longitudinal direction of the handle 4. A vacuum inlet/outlet hole orport 25 is formed in the body of the outer handle 18 and communicateswith the volume 24. A sliding so-called tire valve thumb grip 20encircles the outer handle 18 and is sealed thereto by O-ring sealshaving O-rings 21 in recesses 22 in the grip 20. An O-ring seal is alsodisposed at the proximal end of the handle 4. The grip 20 also has avacuum inlet/outlet 23 for the connection or nipple 35. When the grip 20is slid toward an annular stop 26, the vacuum inlet/outlet 23 is not inalignment with the vacuum inlet/outlet hole 25. However, when the grip20 is slid toward an annular stop 27, the vacuum inlet/outlet 23 and thevacuum inlet/outlet hole 25 are aligned, providing communication betweenthe connection or nipple 35 and the volume 24. Therefore, duringoperation, the grip 20 is slid toward the stop 27 to apply vacuum tostiffen the hollow body or to vent the vacuum to the atmosphere orsupply air at atmospheric pressure to make the hollow body flexibleagain. The grip 20 is slid toward the stop 26 to maintain the stiffenedor flexible condition of the hollow body attained by vacuum or ventingor air supply through the connection or nipple 35. The septum valveassembly 29 is in the form of an end cap which is inserted into theproximal end of the outer handle 18 and provides a so-called septum sealfor insertion of an instrument 44, such as an endoscopy or acolonoscopy, represented by a dot-dash line. End caps with various sizedopenings may be used in dependence on the instrument being used. Theinstrument passes through the hollow body and emerges at the distal tip7. A diaphragm seal is provided between the septum valve assembly 29 andthe inner handle 19.

If the insertion device 1 is non-steerable, the number of tendons 11 mayalso be varied as shown in FIG. 3 to provide stiffness zones. Forexample, a stiffness zone A closest to the distal tip 7 has fourtendons, a stiffness zone B has eight tendons and a stiffness zone Cclosest to the handle 4 has sixteen tendons. A zone with more tendonswill be stiffer than a zone with fewer tendons. The number of tendonsand their location within the zones as well as the number of zones canbe increased or decreased, depending on the application of the device.Vertebrae 12-18, which in this case are seven in number, are also shown.The four tendons in the zone A all end at the termination bushing 31 butare free to slide elsewhere. Four of the eight tendons in zone B, whichdo not extend to zone A, are fixed at the vertebra 14 between zones Aand B, which is therefore referred to as a termination vertebra, but arefree to slide elsewhere. Similarly, eight of the sixteen tendons in zoneC, which do not extend into zones A and B, are fixed at the terminationvertebra 16 between zones B and C but are free to slide elsewhere.

FIG. 4 shows the device 1 with the handle 4 removed, from which it canbe seen that the four steering tendons 11′ of the steering assembly 10continue toward the handle from the tip 7, whereas the non-steeringtendons 11 only run from the termination vertebra 15 to the handle. Itis also seen that as the insertion device is steered, the steeringtendons 11′ on the outside of the bend become shorter and the steeringtendons 11′ on the inside of the bend become longer. FIG. 5 shows asimilar view to FIG. 4, in which it can be seen how a greater number ofvertebrae react to bending. In the case of FIG. 5, eight steeringtendons 11′ extend to the termination bushing 31, whereas sixnon-steering tendons 11 extend from the termination vertebra 18 to thehandle.

In the enlarged view of FIG. 6, a portion of the corrugated tube 30 inthe region of the tip 7 and the termination bushing 31 are shown. Thetendons 11, 11′, which have been omitted in FIG. 6 for the sake ofclarity, are shown in FIG. 7 as extending through the vertebrae 13, 14to the termination bushing 31. A tip restrictor 32 can also be seen atthe tip 7. It may also be seen that an inner liner 33 extends within thecorrugated tube 30. One purpose of the inner liner is to provide asurface on which the instrument will pass smoothly within the corrugatedtube. The corrugated tube 30 may be formed of nylon or another suitablematerial. The inner liner 33 is made from a sheet of white plasticmaterial which has an adhesive coating on one side. The inner liner 33is rolled around an inflatable mandrel and heated in an oven, to form abonded seam 42 (shown in FIGS. 11-13) and is sealed to an inner surfaceof the corrugated tube 30. The corrugations of the corrugated tube 30have peaks and valleys. As viewed from within the corrugated tube 30,the inner liner 33 adheres to the peaks and extends somewhat into thevalleys of the corrugations as dimples. Therefore, as the insertiondevice bends, the inner liner 33 stays tight along the corrugations onthe outside of the bend and crinkles at the inside of the bend. Thepeaks and valleys of the corrugations also need not be of equal lengthalong the length of the corrugated tube 30. For example, 70% of thelength may be peaks and 30% valleys or 80% of the length may be peaksand 20% valleys. These variations will add to the adhesion of the innerliner to the corrugated tube and reduce the formation of dimples.However, a 50/50 corrugation ratio is shown in the figures. The outerjacket 5 may be formed of polyurethane or another suitable materialwhich is similarly a flat sheet that is rolled and seamed. The outerjacket 5 and the inner liner 33 both extend to the termination bushing31, which may be formed of polycarbonate.

The corrugated tube is cuffed in order to prevent leakage paths for thevacuum applied within the hollow body and to protect the material of theinner liner. FIG. 8 illustrates two types of molded corrugation cuffs34, namely a straight cuff on the left and a stepped cuff on the right,of the figure, both with a 50/50 corrugation ratio. FIG. 9 shows theinner handle 19 which is attached to a corrugation cuff 34, as well asthe inner liner 33 that is sealed to the corrugated tube 30 and to theinner handle 19 to prevent a vacuum leakage path.

The perspective view of FIG. 10 illustrates the insertion device 1 inthe region of the tip 7, including the outer jacket 5 extending to thetip, which is not shown in the other figures.

The fragmentary, perspective view of FIG. 11 illustrates the insertiondevice 1 in the region of the tip 7, with the outer jacket removed toreveal the termination bushing 31 at the tip 7, the corrugated tube 30,the vertebrae 13, 14, the tendons 11 or 11′ and the inner liner 33. Itis seen that the tendons slide through channels 37 in the vertebrae.

In FIG. 12, not only the outer jacket 5 but also the tip 7 have beenremoved to show how the tendons 11, 11′ are anchored in the terminationbushing 31. As can been seen, each tendon 11, 11′ passes through arespective hole 40 in the termination bushing 31. Each two tendonstogether have a U-shape in the form of a large staple having acrosspiece 41 extending between two of the holes 40. This avoids thenecessity of welding ends of tendons to a terminating vertebra or ring.The U-shaped tendons and crosspiece are best seen in FIG. 12A.

In FIG. 13, not only the outer jacket 5 and the tip 7 but also thetermination bushing 31 have been removed to show a portion of the innerliner 33 which is sealed on the inner surface of the termination bushing31 for vacuum sealing and smooth movement of the instrument or scope 44.The crosspieces 41 of the tendons 11, 11′ as well as the seam 42 of theinner liner are also clearly shown.

FIG. 14 is a cross-sectional view of the insertion device 1 which istaken through the flexible tip restrictor 32, as seen in the directionof the vertebra 13. Therefore, the outer jacket 5, the vertebra 13 withthe tendons 11, 11′, the corrugated tube 30 with the peaks and valleysand the tip restrictor 32, can be seen.

Representative vertebrae 12-18 are shown in FIGS. 15 and 16. Thevertebra of FIG. 15 is a so-called latch ring constructed for snapinstallation. The vertebra is formed of elastic material which permitsit to be expanded at a parting line and opened at a gap 43, so that itcan be snapped over the corrugated tube 30 between two peaks thereof.Therefore, the vertebra can be installed at any location desired alongthe corrugated tube for support of the tendons. The vertebra shown inFIG. 16 is intended to be placed at an end of the corrugated tube 30,where no expansion and snapping into place are required.

The operation of the variably flexible insertion device 1 will now bedescribed below by making reference to the above-described figures. Ifthe steerable embodiment is used, the device 1 is flexed against thestiffness of the corrugated tube 30, for example upon traversing therectosigmoid junction, by sliding one or more of the knobs 6. In eitherthe steerable or non-steerable embodiment, if it is desired to maintainthat flexed condition for guiding an endoscope, such as a colonoscopy,vacuum is applied at the connection or nipple 35. When suction isapplied to create the vacuum, it causes the inner sleeve 33 and theouter jacket 5 to approach each other with the corrugated tube 30 andthe tendons 11, 11′ sandwiched and frictionally locked therebetween.Therefore, the vacuum connection or nipple 35 acts as a device fortransitioning the hollow body 4, 7, 19, 5, 33, 30 between a relativelyflexible condition and a relatively stiff condition through theapplication of a vacuum. As long as the vacuum is applied, the device 1maintains its flexed condition. The positions of the knobs 6 in FIGS. 1,2, 4 and 5 show that in the flexed condition, the tendons 11′ at theouter periphery of the bend become shorter and the tendons 11′ at theinner periphery of the bend become longer, since they are all fixed inplace at the termination bushing 31.

The tendons or wires are passive elements which are not in tension atany time. The tendons float within the hollow body when it is in theflexible condition, except where they are fixed to termination vertebraeor the termination bushing 31 at the distal end. The tendons arefrictionally locked by the inner sleeve 33 and the outer jacket 5 whenthe hollow body is in the stiff condition. However, in both therelatively flexible condition and the relatively stiff condition, thetendons have no active control imposed on them and are not pulled orconstrained.

When it is desired to resume flexibility of the device 1, the vacuum isvented or replaced by air at ambient or positive pressure. This causesthe inner sleeve 33 and the outer jacket 5 to release the tendons andallows the stiffness of the corrugated tube 30 to place the device 1into its normally flexible condition.

The device is intended to be used in a manner similar to prior artdevices. Therefore, the device will be placed over the endoscope. Theendoscope will then be inserted into the rectum. The device will then bepushed in its flexible condition, to follow the curvature of the scope.The device will then be stiffened, allowing the scope to be pushedforward with less pressure exerted on the colon of the patient. Thisprocedure can be repeated until the scope reaches the cecum.

An alternative use of the device is to aid in small bowel endoscopy. Thedevice is placed over the endoscope. The endoscope is inserted into thepatient transorally, through the stomach and then partially into thesmall bowel. The device is then pushed in its flexible condition, tofollow the curvature of the scope. The device is then stiffened,allowing the scope to be pushed forward without the scope looping in thestomach.

Another use of the device is for aiding in access to internal bodyparts, such as the gallbladder, through an opening of an internal bodycavity, such as the stomach. The device is placed over the endoscope.The endoscope is inserted into the patient transorally, through thestomach and then up against the internal surface of the stomach. Thedevice is then pushed in its flexible condition, to follow the curvatureof the scope. The device is then stiffened, allowing the surgeon tocreate an opening in the stomach wall without the scope looping in thestomach. Once the opening is created, the device and the scope can beadvanced outside the stomach. The device can then be stiffened to createa stable platform to perform surgical procedures outside of the stomach.The device could contain one or more features (i.e. balloons) forsealing the outer periphery of the device to the stomach wall to preventgastric fluids from exiting the stomach.

In each of these procedures described above, the knobs and tendons areused to steer the insertion device within the body as needed, while thecorrugated tube allows the device to be twisted as needed.

1. A method for transmitting torque and variably flexing an insertiondevice for receiving an instrument, the method comprising the followingsteps: providing a hollow body; transmitting torque along the hollowbody with a corrugated tube; applying suction to create a vacuum in thehollow body for placing the hollow body in a relatively stiff condition;relieving the vacuum for placing the hollow body in a relativelyflexible condition; maintaining the hollow body in the relativelyflexible and relatively stiff conditions with tendons disposed withinthe hollow body; and individually adjusting at least some of the tendonsin length for steering a distal end of the hollow body.
 2. The methodaccording to claim 1, which further comprises preventing vacuum leakageand aiding in insertion of the instrument with a liner disposed withinthe corrugated tube.
 3. The method according to claim 2, which furthercomprises adhesively connecting the liner to the corrugated tube.
 4. Themethod according to claim 1, which further comprises carrying out thestep of individually adjusting at least some of the tendons as steeringtendons with knobs each connected to a respective one of the steeringtendons and each sliding in a respective slot formed in a handle at aproximal end of the hollow body.
 5. The method according to claim 1,which further comprises providing the hollow body with an outer jacketand an inner sleeve, providing the tendons at least partly between theouter jacket and the inner sleeve, providing the corrugated tube betweenthe outer jacket and the inner sleeve, and carrying out the step ofapplying suction between the outer jacket and the inner sleeve with atransitioning device for frictionally locking the tendons and thecorrugated tube in place.
 6. The method according to claim 5, whichfurther comprises providing a vacuum connection as the transitioningdevice, and actuating the vacuum connection with a valve at a handle ofthe hollow body.
 7. The method according to claim 1, which furthercomprises guiding the tendons with vertebrae disposed along thecorrugated tube.
 8. The method according to claim 7, which furthercomprises placing the vertebrae between corrugation peaks of thecorrugated tube for guiding the tendons.
 9. The method according toclaim 8, which further comprises snapping the vertebrae onto thecorrugated tube by elastically opening the vertebrae at a parting lineinto a gap.
 10. The method according to claim 7, which further comprisespermitting movement of at least some of the tendons through channelsformed in at least some of the vertebrae.
 11. The method according toclaim 1, which further comprises attaching at least some of the tendonsto a termination bushing at a distal end of the hollow body.
 12. Themethod according to claim 11, which further comprises forming each twoof the tendons into legs of a U-shaped configuration passing throughholes in the termination bushing and being interconnected by acrosspiece extending between two of the holes distally of thetermination bushing.
 13. The method according to claim 7, which furthercomprises attaching some of the tendons to a termination bushing at adistal end of the hollow body as steering tendons, attaching others ofthe tendons to one of the vertebrae as non-steering tendons, andsteering the distal end with the steering tendons.
 14. The methodaccording to claim 1, which further comprises varying the number of thetendons along the hollow body for providing zones of varying stiffness.15. The method according to claim 14, which further comprises providinga greater number of the tendons toward a distal end than toward aproximal end of the hollow body, for increasing stiffness at the distalend.
 16. The method according to claim 2, which further comprisescuffing at least one end of the corrugated tube to prevent vacuumleakage.